Composite planetary gear apparatus

Abstract

The composite planetary gear apparatus according to the present invention can bring about an advantageous effect to prevent fuel efficiency from being lowered stemming from the increased stirring loss of oil. The apparatus comprises a first planetary gear assembly 11 having a sun gear S 1 , pinion gears P 1 , and a ring gear R 1 , and a second planetary gear assembly 12 having a sun gear S 2 , pinion gears P 2 , and a ring gear R 2 . The ring gears R 1 and R 2 surround the pinion gears P 1 and P 2 and are combined together to integrally form a counter drive gear 13 . The counter drive gear 13 is formed with a plurality of through bores 13 c each having an inner end opened at a closed space defined by the first and second planetary gear assemblies 11 and 12 , and an outer end opened at an outer space surrounding the counter drive gear 13.

1. A composite planetary gear apparatus, comprising:
 a first planetary gear assembly including a first sun gear, a plurality of first pinion gears held in mesh with said first sun gear, and a first outer ring member having inner teeth held in mesh with said first pinion gears; 
 a second planetary gear assembly including a second sun gear arranged in axial alignment with said first sun gear, a plurality of second pinion gears held in mesh with said second sun gear, and a second outer ring member having inner teeth held in mesh with said second pinion gears; and 
 an integral outer ring member including said first outer ring member and said second outer ring member, the integral outer ring member surrounds said first pinion gears and said second pinion gears and is surrounded by an outer space, wherein 
 an inner peripheral surface of said integral outer ring member includes the first outer ring member, the second outer ring member, and an annular groove between the first outer ring member and the second outer ring member, 
 an outer peripheral surface of said integral outer ring member includes counter drive gear teeth, 
 a plurality of through bores radially extend from the annular groove, 
 said first planetary gear assembly and said second planetary gear assembly collectively define a closed space held in communication with said outer space through said through bores, and 
 oil from the first pinion gears and the second pinion gears is urged radially outwardly toward the first outer ring member and second outer ring member, respectively, this oil is collected in the annular groove and is discharged through the through bores to lubricate the counter drive gear teeth. 
 
     
     
       2. A composite planetary gear apparatus as set forth in  claim 1 , wherein the through bores are circumferentially equidistantly arranged. 
     
     
       3. A composite planetary gear apparatus as set forth in  claim 1 , wherein an end of each of said through bores is opened at the radially outermost position in the outer peripheral surface of said integral outer ring member. 
     
     
       4. A composite planetary gear apparatus as set forth in  claim 1 , wherein:
 the outer peripheral surface of the integral outer ring member includes an annular bulged portion that extends radially outward, and 
 the annular bulged portion includes the counter drive gear teeth. 
 
     
     
       5. A composite planetary gear apparatus as set forth in  claim 4 , wherein the through bores have a first end opened at a bottom surface of the annular groove and a second end opened at the annular bulged portion between two adjacent teeth of the counter drive gear teeth. 
     
     
       6. A composite planetary gear apparatus as set forth in  claim 1 , wherein each of said through bores have one end opened at a bottom surface of said annular groove and an other end opened at the outer peripheral surface of said integral outer ring member. 
     
     
       7. A composite planetary gear apparatus as set forth in  claim 6 , wherein:
 at least one planetary gear assembly is selected from among said first planetary gear assembly and said second planetary gear assembly, said sun gear, said pinion gears, and said inner teeth of said selected planetary gear assembly being each formed by a helical gear, 
 said annular groove being in the form of a rectangular shape in cross-section taken in the axial direction of said first and second planetary gear assemblies to have a bottom surface and a pair of side surfaces connected to said bottom surface at their respective corner portions, and 
 one end of each of said through bores being opened in the vicinity of one of said corner portions. 
 
     
     
       8. A composite planetary gear apparatus as set forth in  claim 7 , wherein the helical gear is formed so that the oil flowed into the closed space is scooped up in the radially outward and axially inclined direction by the centrifugal force at the time of the rotations of said first and second pinion gears and then collected in the vicinity of the corner portions of the annular groove. 
     
     
       9. A composite planetary gear apparatus, comprising:
 a first planetary gear assembly including a first sun gear, a plurality of first pinion gears held in mesh with said first sun gear, and a first outer ring member having inner teeth held in mesh said first pinion gears; 
 a second planetary gear assembly including a second sun gear arranged in axial alignment with said first gear, a plurality of second pinion gears held in mesh with said second sun gear, and a second outer ring member having inner teeth held in mesh with said second pinion gears; and 
 an integral outer ring member including said first outer ring member and said second outer ring member, the integral outer ring member surrounds said first pinion gears and said second pinion gears and is surrounded by an outer space, wherein 
 an inner peripheral surface of said integral outer ring member includes the first outer ring member, the second outer ring member, and a plurality of grooves between the first outer ring member and the second outer ring member, 
 the grooves are formed circumferentially equidistantly on and along the inner peripheral surface, 
 an outer peripheral surface of said integral outer ring member includes counter drive gear teeth, 
 a plurality of through bores radially extend from the grooves, respectively, 
 said first planetary gear assembly and said second planetary gear assembly collectively define a closed space held in communication with said outer space through said through bores, and 
 oil from the first pinion gears and the second pinion gears is urged radially outwardly toward the first outer ring member and second outer ring member, respectively, this oil is collected in the grooves and is discharged through the through bores to lubricate the counter drive gear teeth.